# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
import random
from util.ip import get_proxies_pool, get_proxies
from scrapy import signals
from scrapy.core.downloader.handlers.http11 import TunnelError
# useful for handling different item types with a single interface
from itemadapter import ItemAdapter


class TutorialSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    async def process_start(self, start):
        # Called with an async iterator over the spider start() method or the
        # maching method of an earlier spider middleware.
        async for item_or_request in start:
            yield item_or_request

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class TutorialDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        # print("TutorialDownloaderMiddleware")
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)

class ResponseUserAgentMiddleware:

    def process_request(self, request, spider):
        # print(111)
        user_agents = ['5555', '6666', '7777']
        request.headers['User-Agent'] = random.choice(user_agents)
        # print("ResponseUserAgentMiddleware")


    def process_response(self, request, response, spider):
        return response

class ResponseCookieMiddleware:

    def process_request(self, request, spider):
        pass


    def process_response(self, request, response, spider):
        return response


class ProxyMiddleware:

    @classmethod
    def from_crawler(cls, crawler):
        s = cls()
        s.settings = crawler.settings
        return s


    def process_request(self, request, spider):
        request.meta['proxy'] = random.choice(self.settings['PROXIES'])


    def process_response(self, request, response, spider):
        return response


class ProxiesPoolMiddleware:
    @classmethod
    def from_crawler(cls, crawler):
        s = cls()
        s.proxy_pool = get_proxies_pool(1)
        return s


    def process_request(self, request, spider):
        ip = random.choice(self.proxy_pool)
        print(f"使用代理{ip['http']}")
        request.meta['proxy'] = ip['http']
        request.meta['ip'] = ip


    def process_response(self, request, response, spider):
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        if isinstance(exception, TunnelError):
            print("代理出现异常, 替换新代理")
            if request.meta['ip'] in self.proxy_pool:
                self.proxy_pool.remove(request.meta['ip'])
                self.proxy_pool.append(get_proxies())
            ip = random.choice(self.proxy_pool)
            print(f"新代理{ip['http']}")
            request.meta['proxy'] = ip['http']
            request.meta['ip'] = ip

        return request



class TunnelProxiesMiddleware:

    _proxy = ('t752.kdltpspro.com', '15818')

    def process_request(self, request, spider):

        # 用户名密码认证
        username = "t16308824584734"
        password = "qfs5ciov"
        request.meta['proxy'] = "https://%(user)s:%(pwd)s@%(proxy)s/" % {"user": username, "pwd": password, "proxy": ':'.join(TunnelProxiesMiddleware._proxy)}

        request.headers["Connection"] = "close"
        return None

    def process_response(self, request, response, spider):
        return response